Polymers having a combination of high strength and moduli, good high temperature properties, and ease of preparation are always of interest for typical thermoplastic uses, such as molding resins and fibers. Shaped parts and fibers made from these polyesters are useful where good mechanical properties and/or moderate temperature resistance are desired. Disclosed herein are polyesters, particularly poly(imide-esters), which have such properties, and are particularly easy to form into useful shapes by melt processing. These polyesters are based on 4,4'-bis(3-hydroxyphenoxy)biphenyl (herein abbreviated as BHBP) as one of the monomeric units. Polyesters, and especially poly(imide-esters) made with this repeat unit usually have a good balance of good physical properties and melt formability.
U.S. Pat. Nos. 4,873,371 and 5,068,457 describe the preparation of BHBP. Both of these patents state that dihydroxy compounds disclosed therein may be used to prepare liquid crystalline polyesters, while '371 at col. 6, lines 33-39 and '457 at col. 7, lines 21-38 describe liquid crystalline polyesters made from these dihydroxy compounds.